# AD 58-15-01: Safety Belt Hook Assembly

- Type: Airworthiness directive
- Status: Current
- Products: Boeing DC-6, DC-6A, DC-6B, DC-7, DC-7B and DC-7C
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Large airplane
- Registered aircraft: 22 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/10D8E6F0E192E0A6862569BC00725804.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/58-15-01

## The airworthiness directive

58-15-01 DOUGLAS: Applies to DC-6 and DC-7 Series Aircraft.

Compliance required by September 1, 1958.

Hook assemblies, P/N CSS1000-D, installed in safety belt assemblies, P/N 5610175, have been found to be understrength due to improper heat treat by the vendor.

All DC-6 and DC-7 Series aircraft equipped with these safety belt assemblies that were manufactured during the months of December 1957, January 1958, and February 1958, are affected. These belts can be identified by the manufacturing date (month and year) stamped on the part number tag sewn on the belt (i.e., date manufactured, December 1957, etc.). Belt assemblies manufactured prior to these dates are satisfactory and all future DC-6 and DC-7 aircraft will have safety belts with proper hook assemblies installed.

All hook assemblies that give a Rockwell reading of 36 or above on the "C" scale are satisfactory. Those that show a Rockwell reading below 36 are unsatisfactory and the belt must be replaced.(Douglas Alert Service Bulletin A-779 for the DC-6 Series and A-321 for the DC-7 Series cover the above subject and describe acceptable inspection and replacement procedures.)

## Affected data sheets (4) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS 4A10](https://openairdocs.org/tcds/4A10): The Boeing Company; names 3 of 3 models: DC-7, DC-7C, DC-7B
- [TCDS 6A3](https://openairdocs.org/tcds/6A3): The Boeing Company; names 1 of 3 models: DC-6A
- [TCDS 6A4](https://openairdocs.org/tcds/6A4): The Boeing Company; names 1 of 2 models: DC-6B
- [TCDS A-781](https://openairdocs.org/tcds/A-781): The Boeing Company; names 1 of 1 models: DC-6

## Registered aircraft it may apply to (OpenAirDocs)

Matched by airframe and engine model; the AD's applicability may narrow it by serial number, part number or equipment.

- Aircraft: 22 (22 by airframe model, 0 by engine model)
- Makers: Douglas 22

Models with the most aircraft:

- [Douglas DC-6B](https://openairdocs.org/model/douglas-dc-6b): 9 aircraft (airframe model)
- [Douglas DC-6A](https://openairdocs.org/model/douglas-dc-6a): 7 aircraft (airframe model)
- [Douglas DC-7](https://openairdocs.org/model/douglas-dc-7): 2 aircraft (airframe model)
- [Douglas DC-7B](https://openairdocs.org/model/douglas-dc-7b): 2 aircraft (airframe model)
- [Douglas DC-6](https://openairdocs.org/model/douglas-dc-6): 1 aircraft (airframe model)
- [Douglas DC-7C](https://openairdocs.org/model/douglas-dc-7c): 1 aircraft (airframe model)

All 6 models: https://openairdocs.org/ad/58-15-01/models.md
Every aircraft: https://openairdocs.org/ad/58-15-01/aircraft.md

Its text cites no advisory circulars or STCs.

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